Over the last several months, the amount the U.S. spends each day on fighting ISIS across Syria and Iraq has increased by millions of dollars, Pentagon figures show. The total cost of the campaign, which hit nearly $5 billion in October, is expected to grow even more as the Obama administration ratchets up its campaign against ISIS, increasing the number of airstrikes it conducts and the military support it provides to Syrian rebel groups as well as deploying American boots on the ground in Syria.

The daily tab for fighting ISIS had already climbed more than 20 percent between May 21 and October 15 of this year, from $9.1 million a day to nearly $11 million, according to the Pentagon’s latest public figures. More than half of those costs came in the form of airstrikes, which the U.S. has employed since August of 2014 to pound Islamic State targets. Munitions, logistics and operational support accounted for the remaining costs, the Pentagon said.

Spending in all four of these categories is expected to grow considerably after the White House’s decision to wade further into the conflict. President Obama’s announcement last month that his would deploy as many as 50 Special Operations soldiers in Syria could require hundreds of additional personnel, analysts say. At the same time, U.S.-led airstrikes in the country, which ground to a near standstill in October, have intensified. Additionally, military officials have said they will continue to increase the supply of arms given to Syrian rebel groups willing to fight ISIS.

“If we find additional groups that are willing to fight ISIL and are capable and motivated, we’ll do more,” Defense Secretary Ash Carter told ABC News last week, using another name for ISIS, which is also called the Islamic State. He did not dismiss the possibility that the U.S. would consider putting even more boots on the ground to defeat the group. “We have to beat ISIL,” Carter said. “We will beat ISIL.”